Water, carbon, climate and life on Earth：练习题

• a.

  It is a positive feedback loop where warming melts permafrost and hydrates, releasing methane that further enhances the greenhouse effect.

• b.

  It is a negative feedback loop where the release of methane triggers high-latitude precipitation that accelerates the carbon burial rate.

• c.

  It is a positive feedback loop where higher temperatures lead to increased cloud cover, reflecting solar radiation and cooling the Arctic.

• d.

  It is a negative feedback loop where increased methane release stimulates microbial growth that sequester more carbon.

• a.

  Increased precipitation enhances the rate of carbonation weathering, removing more \(CO_{2}\) from the atmosphere into river systems as bicarbonate ions.

• b.

  Increased precipitation always leads to higher rates of forest combustion, which releases more carbon into the atmosphere.

• c.

  Increased precipitation saturates soils, preventing the diffusion of \(CO_{2}\) and leading to a build-up in the atmosphere.

• d.

  Higher rainfall levels reduce the salinity of the ocean, which in turn decreases the solubility of carbon in surface waters.

• a.Higher atmospheric \(CO_{2}\) concentrations immediately increase the water-use efficiency of remaining trees, leading to a rapid rise in groundwater levels.
• b.Decreased albedo of the cleared land reflects more solar radiation, leading to a cooling effect that promotes cloud formation and restores rainfall.
• c.Reduced evapotranspiration leads to less regional rainfall, causing further forest dieback and increased carbon release through decomposition.
• d.Increased soil moisture from lack of tree uptake leads to higher rates of photosynthesis in remaining grasses, cooling the local climate.

先自己写一遍答案，再对照解题步骤。

先自己写一遍答案，再对照解题步骤。

先自己写一遍答案，再对照解题步骤。